Robin,

Half-relief, probably not. I was thinking more in terms of mask+clothing
sewn together as a single piece, with some stiffeners[1] and weights to
make it drape/drop, which could be suspended from a single fishing line.

That's pretty close to my (3D) approach, with a head-and-shoulders form in
expanded polystyrene maybe, or wire frame. I think with a single line there
might be a tendency for it to rotate, but there are ways round that.